PHOTOS: Keep Up with the Pope's Trip to Cuba and the United States
Pope Francis greeted a crowd outside the Cathedral Basilica of Saints Peter and Paul on Saturday in Philadelphia before giving a mass about religious tolerance.
The pontiff cracked a smile during the mass in Philadelphia.
Many gathered at the cathedral to hear the pope's homily on Saturday, including many important members of the Catholic church.
The pontiff mad his way through the crowd as he traveled to the Festival of Families in Philadelphia.
On Friday night, the pope celebrated mass at Madison Square Garden in New York City, which was his final night in the Big Apple.
Friday afternoon was Pope Francis' most adorable appointment of the day: Meeting Catholic school students at Our Lady Queen of Angels in Harlem with Cardinal Dolan. Once the school bells ring, the Pope will set off in a motorcade through Central Park to greet New Yorkers before closing out the New York City leg of his trip with evening mass at Madison Square Garden.
Outside of Our Lady Queen of Angels School in Harlem, he stopped to take a few photos with the crowd that had gathered to greet him.
After a morning spent at the United Nations, the pope headed downtown to the World Trade Center to visit the National September 11 Memorial and Museum.
There, the pontiff took some time to pray for all those who lost their lives in in the Sept. 11, 2011, terrorist attacks …
… and paid tribute to the victims by placing flowers on the memorial after he finished praying.
After paying his respects, the Pope headed inside, where he led an interfaith prayer service for peace.
Naturally, the pontiff was greeted by crowds of people, some of whom had been waiting there for hours.
Pope Francis was joined on the stage by religious leaders representing faiths including Islam, Judaism, Christianity, Hinduism and Sikhism.
During the service, a very emotional pope spoke out against religious fanaticism, and encouraged the other religious leaders present to join him in being a force for peace and justice.
He also offered a prayer that had originally been offered by Pope Benedict XVI, who visited the World Trade Center in 2008, before the memorial was completed.
Many of the other leaders present offered their own prayers of peace, and like, Pope Francis – who delivered his address in Spanish – they spoke in their native tongues.
After the service, the pope was treated to a tour of the museum by former New York City Mayor Michael Bloomberg.
The pair was joined by the press for their trip through the exhibition hall.
Things were a bit calmer when Pope Francis also took in the Ladder Company 3 truck alongside the current Archbishop of New York, Cardinal Timothy Dolan.
Pope Francis stopped to shake the hand of a New York Police Department officer outside in the Memorial Plaza.
Bloomberg wasn't the only Mayor present on Friday – the pontiff also made time to meet with the current Mayor of New York, Bill de Blasio, and his wife, Chirlane McCray.
Pope Francis headed out bright and early Friday morning for a visit to the United Nations, where he brightened up staff members' mornings by greeting them with Secretary General Ban Ki-moon.
On his way to the podium to address the U.N. General Assembly, the pontiff was greeted with a standing ovation.
During his speech – which kicked off a meeting of the U.N. Sustainable Development Summit – Pope Francis urged world leaders to work harder to combat global warming.
Nearly 48 hours after arriving, Pope Francis was back at Joint Base Andrews in Maryland, boarding a flight from Washington, D.C., to New York City.
While in D.C., Pope Francis visited the Catholic Charities of the Archdiocese of Washington, where he was greeted by locals …
… and even took a few selfies with them! Talk about a modern pope.
Back at the Vatican Embassy in Washington, D.C., Pope Francis kissed the cheek of a girl waiting in the crowd.
On his final day in Washington, D.C., crowds swarmed as Pope Francis arrived at St. Patrick's Church.
Well-wishers at St. Patrick's grabbed Francis' hand.
This little girl may not remember being blessed by Pope Francis – but judging by her tearful look, her mom sure will!
A highlight of the pope's time in Washington, D.C., was his congressional address. Here, he arrives at the joint meeting of Congress in the Capitol while Secretary of State John Kerry looks on.
Before speaking to Congress, Pope Francis met with the Speaker of the House, John Boehner, on Capitol Hill.
Standing before a joint meeting of Congress, Pope Francis turned to greet Vice President Joe Biden and Speaker of the House Boehner.
During his address, the pope discussed the importance of taking action against climate change and working to improve the lives of those living in poverty.
Pope Francis made history with his speech, becoming the first ever pontiff to address Congress.
After addressing Congress, Pope Francis greeted the crowd waiting outside the Capitol. The pontiff brought crowds out to the National Mall that rivaled the size of a presidential inauguration.